248 The Naturalist in La Plata. 
on the ground, resemble mice rather than birds ; 
indeed, the Quichua name for one of these Synal- 
laxes is ukatchtuka, or mouse-bird. How different 
is the life habit here from what we see in the 
tropical groups—the large birds with immense beaks, 
that run vertically on the trunks of the great forest 
trees ! 
At the extreme southern extremity of the South 
American continent we find several species of Cin- 
clodes, seeking a subsistence like sandpipers on the 
beach ; they also fly out to sea, and run about on 
the floating kelp, exploring the fronds for the small 
marine animals on which they live. In the dreary 
forests of Tierra del Fuego another creeper, Oxyurus, 
is by far the commonest bird. ‘* Whether high up 
or low down, in the most gloomy, wet, and scarcely 
penetrable ravines,” says Darwin, ‘this little bird 
is to be met with;’’ and Dr. Cunningham also 
relates that in these wintry, savage woods he was 
always attended in his walks by parties of these 
little creepers, which assembied to follow him out of 
curiosity. 
To birds placed at so great a disadvantage, by a 
feeble flight and other adverse circumstances, in the 
race of life bright colours would certainly prove 
fatal. It is true that brown is not in itself a pro- 
tective colour, and the clear, almost silky browns 
and bright chestnut tints in several species are 
certainly not protective ; but these species are suf- 
ficiently protected in other ways, and can afford to 
be without a strictly adaptive colour, so long as they 
are not conspicuous. Ina majority of cases, how- 
ever, the colour is undoubtedly protective, the 
